1. Field of the Invention
The present invention relates to an apparatus for interweaving or entwining the fibers of slivers or fiber strands of stretch breakconversion machines, cut-conversion machines, carding operations, drawing operations, etc., with the fiber slivers comprising individual fibers that are initially disposed essentially parallel to one another.
2. Description of the Prior Art
Man-made fibers are produced as endless filaments or tows having a high degree of evenness. For further processing in the secondary spinning stage, and in conformity with their intended application, the filaments or tows are subsequently cut to the desired fiber length, or are stretch broken or cut-converted. Whereas the indiscriminately or randomly oriented cut fiber material must subsequently be separated and carded for renewed drawing and for reorienting the fibers in a parallel position, as well as for producing the fiber sliver, during stretch break-conversion the high uniformity of the tows is retained, and the excellent parallel orientation of the fibers in the slivers is also retained.
The fiber slivers produced from the fiber tows in stretch break-conversion or cut-conversion machines must have a sufficient cohesion so that these slivers can be transported and further processed. This cohesion is often provided by strand structure, fiber crimping, finishing, etc. In certain cases, additional measures are taken, for instance sliver condension, fiber crimping, application of finishing agent, production of a false twist, etc., in order to improve the cohesion of the fiber slivers. Even these measures do not always suffice to assure the required cohesion of the fiber slivers due to the characater of the raw material and/or due to the technology being utilized.
Thus, with the stretch break-conversion of certain raw material, the further processing of the fiber slivers, which are deposited in cans, causes difficulties. Due to insufficient sliver cohesion, the fiber slivers cannot be reliably withdrawn from the can. If the fiber sliver separates lengthwise, the two sliver portions experience different tensions as they are withdrawn from the can. The sliver that remains in the can is suddenly completely withdrawn after a certain period of time. Appropriate monitoring devices become operative and lead to stop of production. Moreover, expensive scrapping of the defective sliver results.
In a similar fashion, via the cut-conversion process, fiber bundles are produced that after being combined to form a fiber sliver do not assure sufficient sliver cohesion. This drawback can be eliminated only after passing through draw frames several times. At high production speeds, the depositing of the fiber sliver in particular causes difficulties, with expensive and complicated sliver-guidance elements having been developed to eliminate this problem.
Finally, with cotton combing machines, the high degree of parallelism of the fibers reduces fiber cohesion in the fiber sliver as a result of the cotton combing process. This can result in shutdown of production when the slivers pass through subsequent draw frames.
With this in mind, an object of the present invention is to develop a procedure for entwining the fibers of fiber slivers where the cohesion of the slivers is improved and where it is possible to transport and further process the fiber slivers without difficulty without limiting the range of application of previously conventional and advantageous processes. Also, an object of the present invention is to provide an apparatus for carrying out this procedure.